MES as an ISO standard?

From: Markus Kuhn (
Date: Mon Jun 30 1997 - 23:23:22 EDT

Full Unicode with all bells and whistles is much to complicated
to have any chance of becoming a full ASCII replacement in the
near future. Therefore, people will stick with simple 8-bit
character sets for many more years and we will not enter the
16-bit character set area very soon. Just look at the many new
ISO 8859 extention proposals to see that this is what is going

What can we do against this problem? Not the idea of a 16-bit
character set scares people, but the gigantic size of Unicode
and all the complex mechanisms that are involved (bidi,
combining chars, etc.)

On the Web page

there is a description the Minimum European Subset of ISO/IEC 10646-1
(MES) defined in ENV 1973:1995.

Are there any plans to make MES or something close to it a new
ISO standard?

I think, it would be an excellent idea to draft a new standard

  ISO 15646:1998 -- Multi-byte coded character set for
  European languages

that specifies MES or a very similar Unicode subset with around
1000 characters. These characters should all have the
following properties:

  - all are from left-to-right scripts
  - all are of approximately the size of latin characters
    (such that say 9x14 pixel character cell terminal emulators
    like xterm, VGA text-mode, and VT100 emulators can display
    them in one single cell)
  - all are non-combining characters and from scripts that
    can be represented using non-combining characters

These are exactly the properties that characters in most ISO 8859
parts also have, and therefore upgrading from ISO 8859-1 to
ISO 15646 will cost only a fraction of what upgrading to full
Unicode (with combing chars, bidi, large ideographic and dingbats
glyphs, etc.) would cost.

Let's make the idea of a 16-bit character set attractive to
developers by defining an ISO character set that is apart from
being a 16-bit character set in no way any more complicated than
ISO 8859-1.

ISO 15646 should be a superset of all ISO 8859 parts (except
arabic and hebrew because of their bidi requirements), as well as
of IBM code pages 437 (DOS) and 1252 (Windows). I think,
MES is already exactly that.

What do you think?


Markus Kuhn, Computer Science grad student, Purdue
University, Indiana, US, email:

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